Mr. Hardy rushed out of his office. He was wearing a crisp white shirt with a red-and-blue striped tie.

Mrs. Doolin handed him the envelope and note. Mr. Hardy read the note and a frown crossed his face. When he finished, he glanced at the warning on the envelope.

“Where’d you get this?” he asked.

Mrs. Doolin nodded toward Alice and Max. “They found it on the sign-in table,” she said.

Mr. Hardy peered at Alice and Max for a moment. Then he looked at the piece of paper again. “Hrmph,” he grunted. He gave the note back to Mrs. Doolin and dropped the envelope in the trash can next to her desk. He waved his hand.

“I’ll take care of this,” Mr. Hardy said. “It’s probably just someone playing a joke. Like the time Billy Sullivan programmed all the classroom whiteboards to display a message that read School’s canceled! Go home! You kids don’t have to worry. I’ll check it out.”

Mr. Hardy turned back toward his office and said, “Mrs. Doolin, can I see you for a moment?”

Mrs. Doolin glanced at Max and Alice. “Thanks for letting us know about this,” she whispered. “I’m sure Mr. Hardy will check it out. I’ll let you two know if we learn anything.”

“Okay,” Alice said.

Mrs. Doolin disappeared into Mr. Hardy’s office. Max and Alice headed for the main entrance. When they reached it, Max gave the heavy metal door a good shove.

“Hey, watch it!” called a voice to their right. It was Doug, one of the kids helping to organize the Olympics. He was a middle school student now, but everyone knew him because he used to be a star athlete at Franklin.

Doug put his hand up to stop the door from hitting him and dropped the edge of the poster he was holding.

As the door closed, Max and Alice noticed an older girl named Millie hanging posters on the other side of the entrance. Nearby, other middle schoolers were spread out on the ground, painting large banners. The banners read One World, One Team and Share the Olympic Spirit. They were filled with Greek-looking letters, images of classical columns, the Acropolis, crowns made from olive branches, and gold medals.

The door banged shut. Doug stared down at Max and Alice.

“Sorry!” Max said. He picked up the end of the poster and handed it back to Doug. Doug grabbed the top corner of the poster. He went back to sticking it to the wall with masking tape.

“It’s okay,” Doug said. “Just try to be more careful.”

“Okay,” Max said. He and Alice turned and headed down the front steps. But before they hit the last one, Max stopped short.

“Hang on,” he said. “What if Mr. Hardy’s wrong and that Olympic threat isn’t a joke?”

Alice stopped and shrugged. “I don’t know,” she said. “What can we do about it?”

“We can investigate!” Max said. Max was always investigating something. His father was a police detective. Max wanted to be a scientist. He went to special camps during vacation weeks and in the summer. The previous summer he’d spent a week at a detective camp, where they learned how to dust for fingerprints and solve mysteries.

“We can start by getting that envelope. Maybe we can dust it for fingerprints or something.” Max pointed to the window of Mr. Hardy’s office. It was just to the left of the front door. They could see Mr. Hardy at his desk talking on the telephone. Mrs. Doolin was sitting nearby. “If we hurry, we can get the envelope from the trash before they’re done!”

Alice nodded. “All right, good idea,” she said. “Let’s go!”

They ran back up the steps and carefully slipped inside the front door. Max peeked into the main office. The room was empty, but they could hear Mr. Hardy’s voice behind his closed door.

“They’re still in there,” Max said. “Now’s our chance.”

They tiptoed into the room and made straight for the trash can. Max dropped down and rummaged through the trash. He pulled up different scraps of paper until he found the threatening envelope. Just as he picked it up, they heard Mr. Hardy put down his phone.

Alice put her finger to her lips. She pointed at Mr. Hardy’s door and motioned for Max to follow her. Max slipped the envelope into his back pocket as they sneaked closer. They didn’t have to get very close to hear Mrs. Doolin and Mr. Hardy talking.

“Well, what did the chief of police say?” Mrs. Doolin asked. “That’s the second threat we’ve gotten this week about the Olympics! Now will she do something about it?”

“She’s going to send a police officer to the school for the games,” Mr. Hardy said. “But I really hope we don’t have any other problems.”

“Why?” Mrs. Doolin asked.

“Because if we get any other threats, the chief of police said we’ll have to cancel the Olympics!”